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Section 06: Cross-Target Codegen Verification

Status: Not Started Goal: Add FileCheck-based ABI assertions for non-host targets and a mandatory rule requiring cross-target evidence for ABI-sensitive changes.

Success Criteria:

  • Non-host FileCheck tests exist and pass — satisfies mission criterion “cross-target verification”
  • --target end-to-end test works (compile-only, not execute) — satisfies mission criterion “non-host target testing”
  • codegen-rules.md contains the cross-target rule — satisfies mission criterion “rules documented”

Context: Research found extensive cross-target infrastructure (802 lines in cross.rs):

  • ori_llvm/tests/aot/cross.rs: 30+ tests for target triple parsing, platform detection, CPU features, data layout, pointer sizes across 8 supported targets
  • ori_llvm/src/aot/target_features.rs + tests.rs: Arch enum, TargetTripleComponents, alias canonicalization (arm64→aarch64)
  • The compiler CAN create TargetConfig for non-host targets and query data layouts
  • Cross-target LLVM IR emission is structurally possible (target triple flows to TargetMachine)
  • Gap: no tests verify actual LLVM IR emission for non-host targets — only triple parsing and data layout queries. No --target CLI end-to-end test.
  • Related bug: BUG-04-045 (arm64 vs aarch64 mismatch in cross-compilation)

Reference implementations:

  • Go test/codegen/README:17-26: “host-architecture testing is the default for performance reasons, but comprehensive all-architecture checks are recommended after compiler changes”
  • Rust: cross-compile test suite with FileCheck for IR verification

Depends on: Section 01.

06.1 Non-Host FileCheck Tests

File(s): compiler/ori_llvm/tests/codegen/, compiler/ori_llvm/tests/aot/cross.rs

Add FileCheck tests that emit LLVM IR for a non-host target and verify ABI-sensitive attributes (sret, calling conventions, struct passing, signedness).

  • Write FileCheck tests targeting aarch64 (assuming x86_64 host) or vice versa:

    • Test 1: Verify sret attribute on ARM64 for structs >16 bytes (codegen-rules.md §AB-4)
    • Test 2: Verify c_char signedness handling in FFI declarations
    • Test 3: Verify calling convention attributes for the target
    • Test 4: Verify aggregate passing mode (direct vs indirect threshold at 16 bytes)

  • Use the existing ori_test_harness FileCheck infrastructure (// CHECK:, // CHECK-NOT:, etc.) with a target override mechanism:

    • The test creates a TargetConfig::from_triple("aarch64-unknown-linux-gnu") (or equivalent)
    • Emits LLVM IR using the non-host target
    • Runs FileCheck against the emitted IR

  • Subsection close-out (06.1) — MANDATORY before starting 06.2:

    • All tasks above are [x]
    • Update this subsection’s status in section frontmatter to complete
    • Run /improve-tooling retrospectively on THIS subsection
    • Run /sync-claude to check if code changes affect CLAUDE.md or rules files

06.2 —target End-to-End Test

File(s): compiler/oric/, compiler/ori_llvm/tests/

Add an integration test that exercises the full compile path for a non-host target (compile-only, not link/execute).

  • Write integration test:

    • Compile a simple Ori program targeting a non-host triple
    • Verify: compilation succeeds (exit code 0)
    • Verify: emitted LLVM IR contains the correct target triple
    • Verify: data layout matches the target (not the host)
    • This is compile-only — no linking, no execution (we don’t have a cross-linker in CI)

  • If ori build --target aarch64-unknown-linux-gnu doesn’t exist yet, add the --target flag to the CLI:

    • Pass the triple through to TargetConfig::from_triple()
    • Wire through to TargetMachine creation in ori_llvm
    • This may already work — check if the existing cross-compilation infrastructure supports it end-to-end

  • Subsection close-out (06.2) — MANDATORY before starting 06.3:

    • All tasks above are [x]
    • Update this subsection’s status in section frontmatter to complete
    • Run /improve-tooling retrospectively on THIS subsection
    • Run /sync-claude to check if code changes affect CLAUDE.md or rules files

06.3 Cross-Target Verification Rule

File(s): .claude/rules/codegen-rules.md, .claude/rules/tests.md

  • Add rule to codegen-rules.md (new subsection in §9 Verification or §2 ABI):

    • ABI-, layout-, calling-convention-, or signedness-sensitive changes MUST include at least one non-host target FileCheck assertion
    • The assertion must verify the specific ABI attribute being changed (sret, calling convention, struct passing, c_char signedness)
    • Use the existing ori_test_harness FileCheck harness with TargetConfig::from_triple()
    • The rule applies to changes touching: codegen-rules.md §AB-* (ABI classification), §NR-* (narrowing), §TM-* (trampolines), §RT-* (runtime contract)

  • Add cross-reference in tests.md linking to the cross-target rule in codegen-rules.md

  • Subsection close-out (06.3) — MANDATORY before completing section:

    • All tasks above are [x]
    • Update this subsection’s status in section frontmatter to complete
    • Run /improve-tooling retrospectively on THIS subsection
    • Run /sync-claude to check if code changes affect CLAUDE.md or rules files

06.R Third Party Review Findings

  • None.

06.N Completion Checklist

  • All subsections (06.1-06.3) complete
  • Non-host FileCheck tests pass
  • —target end-to-end test passes
  • Rule documented in codegen-rules.md
  • timeout 150 ./test-all.sh passes
  • /tpr-review — independent dual-source review clean
  • /impl-hygiene-review — implementation hygiene clean
  • /improve-tooling — section-close sweep
  • /sync-claude — section-close doc sync